Still in Concession 20 here but now south of the highway.
This was somewhere in the band of dunes around Lat. 29.083397°, Long. 18.934628°.
Of course, looking at this photo now, the glaring error is that the drill hand is not wearing a safety helmet. But then the rig has pulled off the hole, so maybe it's idle.
I know the rig has pulled off the hold because the drill hand is standing on the front end of the mud-bath. The hole would be about a foot to the right of his feet.
As a seismologist, my job was to calculate static corrections to apply to the seismic data we were gathering so that the images would make sense when processed. To do this we had to drill down below the surface weathering. I'd then lower a geophone down the hole, connect it to a seismograph, then strike a metal plate at the surface with a sledgehammer. The seismograph would record how long it took for the hammer blow to reach the geophone. I'd then pull the geophone up a know distance and repeat. Then, back in the office I'd draw all this out on graph paper, make a best fit line and calculate the speed of sound though the weathered layer which would give me the static correction for that location.
Most of the holes were 80 – 100 meters deep but in a few places I recall pushing out to 300 meters. 300 meters of armored cable is a significant weight and pulling the geophone up from those depths by had was a bear!
Not particularly glamorous.
The drillers were probably the crew members who spent most of their time out in the sun. Surveyors were out in the morning and back in the office in the afternoon, the observers would be in and out of the recording truck and their land Rovers all day, the mechanics would be in and out of their workshop and I'd shuttle out when the driller called and return to the office as soon as I had my data.
The drill here is a Mayhew 1000 mounted on a MOL 6×6 truck. MOL is a Belgian transport solutions company founded in 1944 – I'm guessing shortly after liberation. They weren't the prettiest trucks but they got the job done.
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